Most likely between 50-55% overall. I don't think the PS3 will catch the Wii and it's mainly because the PS3 only sells about 50K-70K a week in Japan during the holiday season. The wii sells 100-150K. Even though the PS3 is outselling the Wii by about 10K-15K right now during the off season, even if then did that for a full year every year, it would only be 780K a year they would gain. The Wii is over 5 million ahead of the PS3. We all know the Wii will get another price cut in the near future. So chances are very good that the Wii will hold 50-55% of the market from here on out. I don't think the Wii will be on the market 5 years from now.
I think the PS3 won't last as long as the PS2. The PS3 isn't selling like the PS2 did either. The PS3 has been out for 4yrs -4months. It has sold 48,163,035. In the same time period the PS2 sold 68,739,446 units. The PS2 launched in Japan on March 4, 2000. So the PS3 is over 20 million behind the PS2. The Wii is 17 million units ahead of the of the PS2 (maybe a bit more since it launch a week after the PS3) in the same time period.
Yes, I'm aware that the PS3 will get a price cut as well, but I think the Wii's price cut will nulify that and sales will be pretty close during those surges. I also don't think a Wii2 will be out next year. Most likely it will be announced sometime next year, but I think both the Wii and XBox 360 will have new consoles in 2013. The 360 is still doing very well and Microsoft really wants to push Kinect this year and next. Bring out a new 360 in 2012 would not help Kinect, so that's not going to happen. There's no doubt all 3 companies are working on new hardware right now.